Student or Learner
Bats have a problem: how to find their way around in the dark they hunt at flight, and cannot use light to help them find prey and avoid obstacles. You might say that this is a problem of their own making one that they could avoid simply by changing their habits and hunting by day. But the daytime economy is already heavily exploited by other creatures such as birds. Given that there is a living to be made at night, and given that alternative day time trades are thoroughly occupied, natural selection has favored bats that make a go of the night-hunting trade. It is probable that the nocturnal trades go way back in the ancestry of all mammals. In the time when the dinosaurs. dominated the daytime economy, our mammalian ancestors probably only managed to survive at all because they found ways of scraping a living at night Only after the my stenos mass extinction of the dinosaurs about 65 million years ago were our ancestors able to emerge into the day light in any substantial numbers
Is this "scraping a living" similar to "make both ends meet" or "live from hand to mouth"?
See the answers on other threads.
I'm not a teacher. I speak American English. I've tutored writing at the University of Southern Maine and have done a good deal of copy editing and writing, occasionally for publication.